超晚播条件下密度和追氮时期对淮北地区小麦产量及品质的影响

为了实现安徽淮北地区晚播小麦高产优质栽培，以目前该地区种植面积最大的强筋小麦品种‘烟农19’为材料，采用两因素随机区组设计，研究了小麦超晚播（11月21日，较适宜播期晚30天左右）条件下，密度、追氮时期对小麦产量和品质的影响。结果表明：密度和追肥时期对超晚播小麦籽粒产量影响差异显著，以密度450×104株/hm2、孕穗期追肥处理的产量最高，为7846.5 kg/hm2。密度对穗数和穗粒数影响显著，每公顷穗数随着密度的增加而增加；穗粒数随密度的增加而减少。追氮时期对千粒重影响显著，随追氮时期的推迟而增加。增加密度和推迟追氮时期，旗叶叶片光化学最大效率(Fv/Fm)和PSⅡ的活性(Fv/Fo)提高，增大了PSⅡ的潜在活性，有利于叶片所吸收的光能较充分地用于光合作用。追氮时期对小麦品质的影响差异显著，随着追氮时期的延迟，蛋白质含量、湿面筋含量和沉降值呈增加趋势，试验结果表明推迟追肥至孕穗期可以改善超晚播条件下强筋小麦的籽粒品质。

Effect of Density and Topdressing Time of Nitrogen on Yield and Quality of Wheat in Huaibei Area Under Super-late Sowing

In order to find out the cultivation pattern of late sown wheat for high yield and good quality in the Huaibei region of Anhui Province, wheat cultivar, ‘Yannong 19’ which is the most widely cultivated in the area of Huaibei region, was used to study the effects of different density and nitrogen topdressing time on yield and quality of wheat under super-late sowing condition (21/11, about 30 days later than the conventional sowing date). The experiments was conducted in a field, three seeding density and three topdressing time of nitrogen were set, they are M1 (300×104 plant/hm2), M2 (375×104 plant/hm2) and M3 (450×104 plant/hm2), and returning green stage (T1), jointing stage (T2) and booting stage (T3), respectively. The experiment was a randomized block design with three replications. The results showed that, density and nitrogen topdressing time had significant effect on the grain yield of super-late sowed wheat. The highest (7846.5 kg/hm2) grain yield was found under density of 450×104 plant/hm2 and topdressing nitrogen at booting stage. With the density increasing, the number of ears per hectare increased while grain number per spike decreased significantly. With the delay of topdressing time of nitrogen, the 1000-grain weight increased significantly. With the density increased and nitrogen topdressing time delayed, the maximum photochemical efficiency (Fv/Fm) and the PSⅡ activity (Fv/Fo) were improved, which enable flag leaves to absorb more light energy. Protein content, wet gluten content and sedimentation value of wheat grains raised with topdressing time delayed. So delay the topdressing time to the booting stage could improve the grain quality of strong gluten wheat under super-late sowing.